JBoss AS 7: How to clean up tmp?

I noticed that in my JBoss Application Server 7 installation under standalone/tmp I have 400 MB of files related to past deployments, some of them a few months old.

How is it cleaned up? Should it happen automatically? Is there a tool for it? Can I just remove all those files myself?

As you know JBoss is a purely filesystem based installation. To install you simply unzip a file and thats it. Once you install a certain folder structure is created by default and as you run the JBoss instance for the first time, it creates additional folders for runtime operation. For comparison here is the structure of JBoss AS 7 before and after you start for the first time

Before

jboss-as-7
 |
 |---> standalone
 |      |----> lib
 |      |----> configuration
 |      |----> deployments
 |      
 |---> domain
 |....
 

After

jboss-as-7
     |
     |---> standalone
     |      |----> lib
     |      |----> configuration
     |      |----> deployments
     |      |----> tmp
     |      |----> data
     |      |----> log
     |      
     |---> domain
     |....

As you can see 3 new folders are created (log, data & tmp). These folders can all be deleted without effecting the application deployed in deployments folder unless your application generated Data that's stored in those folders. In development, its ok to delete all these 3 new folders assuming you don't have any need for the logs and data stored in "data" directory.

For production, ITS NOT RECOMMENDED to delete these folders as there maybe application generated data that stores certain state of the application. For ex, in the data folder, the appserver can save critical Tx rollback logs. So contact your JBoss Administrator if you need to delete those folders for any reason in production.

Good luck!

Files related for deployment (and others temporary items) are created in standalone/tmp/vfs (Virtual File System). You may add a policy at startup for evicting temporary files :

-Djboss.vfs.cache=org.jboss.virtual.plugins.cache.IterableTimedVFSCache 
-Djboss.vfs.cache.TimedPolicyCaching.lifetime=1440

I do not have experience with version 7 of JBoss but with 5 I often had issues when redeploying apps which went away when I cleaned the work and tmp folder. I wrote a script for that which was executed everytime the server shut down. Maybe executing it before startup is better considering abnormal shutdowns (which weren't uncommon with Jboss 5 :))